Re: [PATCH v7 4/8] perf jevents: Support more event fields

From: Robin Murphy
Date: Wed Aug 23 2023 - 05:29:39 EST


On 2023-08-21 09:36, Jing Zhang wrote:
The previous code assumes an event has either an "event=" or "config"
field at the beginning. For CMN neither of these may be present, as an
event is typically "type=xx,eventid=xxx".

If EventCode and ConfigCode is not added in the alias JSON file, the
event description will add "event=0" by default. So, even if the event
field is added "eventid=xxx" and "type=xxx", the CMN events final
parsing result will be "event=0, eventid=xxx, type=xxx".

Therefore, when EventCode and ConfigCode are missing in JSON, "event=0"
is no longer added by default. And add EventIdCode and Type to the event
field.

I compared pmu_event.c before and after compiling with JEVENT_ARCH=all,
they are consistent.

Signed-off-by: Jing Zhang <renyu.zj@xxxxxxxxxxxxxxxxx>
---
tools/perf/pmu-events/jevents.py | 20 ++++++++++++++++----
1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/tools/perf/pmu-events/jevents.py b/tools/perf/pmu-events/jevents.py
index f57a8f2..369c8bf 100755
--- a/tools/perf/pmu-events/jevents.py
+++ b/tools/perf/pmu-events/jevents.py
@@ -275,11 +275,14 @@ class JsonEvent:
}
return table[unit] if unit in table else f'uncore_{unit.lower()}'
- eventcode = 0
+ eventcode = None
if 'EventCode' in jd:
eventcode = int(jd['EventCode'].split(',', 1)[0], 0)
if 'ExtSel' in jd:
- eventcode |= int(jd['ExtSel']) << 8
+ if eventcode is None:
+ eventcode = int(jd['ExtSel']) << 8
+ else:
+ eventcode |= int(jd['ExtSel']) << 8
configcode = int(jd['ConfigCode'], 0) if 'ConfigCode' in jd else None
self.name = jd['EventName'].lower() if 'EventName' in jd else None
self.topic = ''
@@ -317,7 +320,11 @@ class JsonEvent:
if precise and self.desc and '(Precise Event)' not in self.desc:
extra_desc += ' (Must be precise)' if precise == '2' else (' (Precise '
'event)')
- event = f'config={llx(configcode)}' if configcode is not None else f'event={llx(eventcode)}'
+ event = None
+ if eventcode is not None:
+ event = f'event={llx(eventcode)}'
+ elif configcode is not None:
+ event = f'config={llx(configcode)}'
event_fields = [
('AnyThread', 'any='),
('PortMask', 'ch_mask='),
@@ -327,10 +334,15 @@ class JsonEvent:
('Invert', 'inv='),
('SampleAfterValue', 'period='),
('UMask', 'umask='),
+ ('NodeType', 'type='),
+ ('EventIdCode', 'eventid='),

FWIW, this smells like another brewing scalability problem, given that these are entirely driver-specific. Not sure off-hand how feasible it might be, but my instinct says that a neat solution would be to encode them right in the JSON, e.g.:

"FormatAttr": { "type": 0x5 }

such that jevents should then only really need to consider whether an event is defined in terms of a raw "ConfigCode", one or more "FormatAttr"s which it can then parse dynamically, or reasonable special cases like "EventCode" (given how "event" is one of the most commonly used formats).

Thanks,
Robin.

]
for key, value in event_fields:
if key in jd and jd[key] != '0':
- event += ',' + value + jd[key]
+ if event:
+ event += ',' + value + jd[key]
+ else:
+ event = value + jd[key]
if filter:
event += f',{filter}'
if msr: